Thread: GearBox.
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Old 11-11-2023, 09:38 PM
RRPhil RRPhil is offline
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Quote:
Originally Posted by Henrym3 View Post
Can anyone pick fault with those solenoid readings.....
156mA is the minimum solenoid current (i.e. solenoid is off) and 780mA is the maximum solenoid current (i.e. solenoid is fully on). The exception to this is Pressure Actuator (i.e. solenoid) 1 which sets the mains pressure and this works the opposite way around. It defaults to maximum pressure when no current is applied. This is so the transmission can limp home in failsafe mode if the transmission loses all electrical power.

Your table shows Pressure Actuator 1 at 156mA, which you would never normally see unless the transmission were on wide-open throttle transmitting maximum torque. Usually, you would expect to see a much higher current than this as the controller modulates the mains pressure in proportion to engine torque to ensure smooth engagement of the clutches. This implies that the transmission is in failsafe mode (i.e. defaults to maximum mains pressure).

Pressure Actuator 4 controls the torque converter lock-up clutch, so 156mA on this solenoid just means the LUC is not activated (low gear/low speed). On the other hand, it could also mean the transmission is in failsafe mode as the LUC is deliberately not engaged in failsafe.

That leaves solenoids 2, 3 & 5. According to your table, solenoids 2 & 3 are fully on and solenoid 5 is fully off. This combination would normally arise only in 3rd gear but, even then, you would never expect to see 2 & 3 at maximum current unless the car was accelerating on WOT. Clearly, therefore, these values are not normal.



Phil
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